Velodyne Digital DrivePLUSSeries - Manual (Page 35)

RECOMMENDED PARAMETER ADJUSTMENT
ORDER FOR MANUAL-EQ OPTIMIZATION
The recommended order for modifying parameters during Manual-EQ is described below. As you make changes observe the frequency
response and how the system sounds to you to evaluate the impact of each parameter change.
For examples of the Manual-EQ optimization process see the Digital Drive PLUS User Interface Manual.
For Manual-EQ optimization:
1. Perform Auto-EQ PLUS optimization to get a good baseline to start your Manual-EQ optimization. During the Auto-EQ PLUS optimization,
note the rolloff frequency and slope of your satellites when the subwoofer mutes itself. If you miss the mute of the subwoofer during
the Auto-EQ PLUS process, you can still see it by pushing the Mute button once you are running Manual-EQ.
2. Start Manual-EQ. Don’t forget to have the Sweep Tone CD playing.
3. Allow the subwoofer and CD signal to sync.
4. Once synced, make sure that you are in the Setup preset. If you want to change a different preset, make sure you are in that one,
but remember that any changes to the preset parameters will no longer be global as when done with the Setup preset. Because of
this, we recommend that you perform your Manual-EQ in the Setup preset.
5. If you missed noting the rolloff frequency and slope of your satellites during the Auto-EQ PLUS optimization, push the Mute button in
the Windows Setup Program or on the remote control. Note the rolloff frequency and slope of your satellites.
6. Examine the results of the Auto-EQ PLUS optimization for low-pass crossover frequency, low-pass slope, and phase.
7. Choose to use these settings or adjust to match the values you arrived at from the muting step. Bear in mind that these settings
may not match the measurement of your satellites because Auto-EQ PLUS measures and compares actual averages of the summed
subwoofer-to-satellite frequency response. It is worth writing them down or remembering them in case you change them to match
the satellites and find that you cannot get a smooth and reasonably flat response.
8. Adjust polarity. Some crossover combinations and some equipment require you to invert the polarity of your Digital Drive PLUS
subwoofer and you cannot achieve a reasonably flat response unless you do.
9. If you feel that the volume should be changed, do so now.
10. Begin by modifying the crossover frequency, mentally comparing how minimal dips are as well as how linear the overall response
is. Sometimes it is easiest to compare character to either side of the current setting. Leave it at the best setting.
11. Next, change the crossover slope with the same consideration in mind. Leave it at the best setting.
12. Similarly, change the phase. If you have achieved a smooth response but have a large dip at the crossover still, you should
probably start with a setting of 90° as the crossover blend may be in quadrature.
13. Because crossover frequency, slope, and phase are interrelated, it is best to adjust the crossover, slope, and phase one more time.
14. Now is the time to work the parametric filters to smooth the response. Change to the first page of either the System Response
screen in the TV screen interface or the Frequency Response and Parameters screen in the Windows Setup Program. These are
the screens that show the frequency response graph. The following sub-steps describe adjusting these filters using the Windows
Setup Program. If you’re using the TV screen interface, use the appropriate remote control buttons to adjust the filters instead of
the mouse.
a. Locate the peaks in the response and order them from largest to smallest.
b. Use your mouse to click the diamond-shaped frequency marker for the EQ filter with the frequency closest to that of the
largest peak. Drag the frequency marker horizontally to the frequency of the peak and then down in level. A horizontal
line with a diamond-shaped marker at each of its ends appears at the EQ’s minimum. This horizontal line is the filter’s
bandwidth control.
c. Use your mouse to click one of the bandwidth markers and horizontally drag it in or out to adjust the EQ width. Try to find
the value that performs the least modification to the frequency response nearby the peak. Keep in mind that large lumps
are still peaks; they just have a wider bandwidth (or lower Q).
d. Continue to the next highest peak, repeating Steps 14a through 14c.
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Digital Drive PLUS User’s Manual RECOMMENDED PARAMETERS